CO-oximeter

Measurement of greater numbers of wavelengths enables the instrument to distinguish between these and carboxyhemoglobin,-COHb, methemoglobin -metHb, other hemoglobin moieties and 'background' light-absorbing species.

Traditionally, measurement is made from arterial blood processed in a specific device designed to be able to measure proportions of multiple components of several hemoglobin moieties using multi-wavelength spectrophotometry and complex, but straightforward internal computations.

While these units still are in wide use, blood gas analyzers with integral CO-oximetry modules have also been developed and successfully marketed by several manufacturers.

For any system making these measurements it is critical that the device clearly distinguish between Oxygen Saturation' and Fractional Oxyhemoglobin" .

In normal subjects the values are nearly identical-thus leading to terminologic and possibly clinical confusion.